xref: /freebsd/sys/dev/xen/control/control.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause AND BSD-4-Clause
3  *
4  * Copyright (c) 2010 Justin T. Gibbs, Spectra Logic Corporation
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14  *    substantially similar to the "NO WARRANTY" disclaimer below
15  *    ("Disclaimer") and any redistribution must be conditioned upon
16  *    including a substantially similar Disclaimer requirement for further
17  *    binary redistribution.
18  *
19  * NO WARRANTY
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
28  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGES.
31  */
32 
33 /*-
34  * PV suspend/resume support:
35  *
36  * Copyright (c) 2004 Christian Limpach.
37  * Copyright (c) 2004-2006,2008 Kip Macy
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. All advertising materials mentioning features or use of this software
49  *    must display the following acknowledgement:
50  *      This product includes software developed by Christian Limpach.
51  * 4. The name of the author may not be used to endorse or promote products
52  *    derived from this software without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
55  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
56  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
57  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
58  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
59  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
60  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
61  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
62  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
63  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  */
65 
66 /*-
67  * HVM suspend/resume support:
68  *
69  * Copyright (c) 2008 Citrix Systems, Inc.
70  * All rights reserved.
71  *
72  * Redistribution and use in source and binary forms, with or without
73  * modification, are permitted provided that the following conditions
74  * are met:
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  *
81  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
82  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
83  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
84  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
85  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
86  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
87  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
88  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
89  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
90  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
91  * SUCH DAMAGE.
92  */
93 #include <sys/cdefs.h>
94 /**
95  * \file control.c
96  *
97  * \brief Device driver to repond to control domain events that impact
98  *        this VM.
99  */
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/kernel.h>
104 #include <sys/malloc.h>
105 
106 #include <sys/bio.h>
107 #include <sys/bus.h>
108 #include <sys/conf.h>
109 #include <sys/disk.h>
110 #include <sys/fcntl.h>
111 #include <sys/filedesc.h>
112 #include <sys/kdb.h>
113 #include <sys/module.h>
114 #include <sys/mount.h>
115 #include <sys/namei.h>
116 #include <sys/proc.h>
117 #include <sys/reboot.h>
118 #include <sys/rman.h>
119 #include <sys/sched.h>
120 #include <sys/taskqueue.h>
121 #include <sys/types.h>
122 #include <sys/vnode.h>
123 #include <sys/sched.h>
124 #include <sys/smp.h>
125 #include <sys/eventhandler.h>
126 #include <sys/timetc.h>
127 
128 #include <geom/geom.h>
129 
130 #include <machine/_inttypes.h>
131 #if defined(__amd64__) || defined(__i386__)
132 #include <machine/intr_machdep.h>
133 
134 #include <x86/apicvar.h>
135 #endif
136 
137 #include <vm/vm.h>
138 #include <vm/vm_extern.h>
139 #include <vm/vm_kern.h>
140 
141 #include <xen/xen-os.h>
142 #include <xen/blkif.h>
143 #include <xen/evtchn.h>
144 #include <xen/gnttab.h>
145 #include <xen/xen_intr.h>
146 
147 #include <xen/hvm.h>
148 
149 #include <contrib/xen/event_channel.h>
150 #include <contrib/xen/grant_table.h>
151 
152 #include <xen/xenbus/xenbusvar.h>
153 
154 bool xen_suspend_cancelled;
155 /*--------------------------- Forward Declarations --------------------------*/
156 /** Function signature for shutdown event handlers. */
157 typedef	void (xctrl_shutdown_handler_t)(void);
158 
159 static xctrl_shutdown_handler_t xctrl_poweroff;
160 static xctrl_shutdown_handler_t xctrl_reboot;
161 static xctrl_shutdown_handler_t xctrl_suspend;
162 static xctrl_shutdown_handler_t xctrl_crash;
163 
164 /*-------------------------- Private Data Structures -------------------------*/
165 /** Element type for lookup table of event name to handler. */
166 struct xctrl_shutdown_reason {
167 	const char		 *name;
168 	xctrl_shutdown_handler_t *handler;
169 };
170 
171 /** Lookup table for shutdown event name to handler. */
172 static const struct xctrl_shutdown_reason xctrl_shutdown_reasons[] = {
173 	{ "poweroff", xctrl_poweroff },
174 	{ "reboot",   xctrl_reboot   },
175 	{ "suspend",  xctrl_suspend  },
176 	{ "crash",    xctrl_crash    },
177 	{ "halt",     xctrl_poweroff },
178 };
179 
180 struct xctrl_softc {
181 	struct xs_watch    xctrl_watch;
182 };
183 
184 /*------------------------------ Event Handlers ------------------------------*/
185 static void
186 xctrl_poweroff(void)
187 {
188 	shutdown_nice(RB_POWEROFF|RB_HALT);
189 }
190 
191 static void
192 xctrl_reboot(void)
193 {
194 	shutdown_nice(0);
195 }
196 
197 #if !defined(__amd64__) && !defined(__i386__)
198 static void
199 xctrl_suspend(void)
200 {
201 	printf("WARNING: xen/control: Suspend not supported!\n");
202 }
203 #else /* __amd64__ || __i386__ */
204 static void
205 xctrl_suspend(void)
206 {
207 #ifdef SMP
208 	cpuset_t cpu_suspend_map;
209 #endif
210 
211 	EVENTHANDLER_INVOKE(power_suspend_early);
212 	xs_lock();
213 	stop_all_proc();
214 	xs_unlock();
215 	suspend_all_fs();
216 	EVENTHANDLER_INVOKE(power_suspend);
217 
218 #ifdef EARLY_AP_STARTUP
219 	MPASS(mp_ncpus == 1 || smp_started);
220 	thread_lock(curthread);
221 	sched_bind(curthread, 0);
222 	thread_unlock(curthread);
223 #else
224 	if (smp_started) {
225 		thread_lock(curthread);
226 		sched_bind(curthread, 0);
227 		thread_unlock(curthread);
228 	}
229 #endif
230 	KASSERT((PCPU_GET(cpuid) == 0), ("Not running on CPU#0"));
231 
232 	/*
233 	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME.
234 	 */
235 	bus_topo_lock();
236 	if (DEVICE_SUSPEND(root_bus) != 0) {
237 		bus_topo_unlock();
238 		printf("%s: device_suspend failed\n", __func__);
239 		return;
240 	}
241 
242 #ifdef SMP
243 #ifdef EARLY_AP_STARTUP
244 	/*
245 	 * Suspend other CPUs. This prevents IPIs while we
246 	 * are resuming, and will allow us to reset per-cpu
247 	 * vcpu_info on resume.
248 	 */
249 	cpu_suspend_map = all_cpus;
250 	CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
251 	if (!CPU_EMPTY(&cpu_suspend_map))
252 		suspend_cpus(cpu_suspend_map);
253 #else
254 	CPU_ZERO(&cpu_suspend_map);	/* silence gcc */
255 	if (smp_started) {
256 		/*
257 		 * Suspend other CPUs. This prevents IPIs while we
258 		 * are resuming, and will allow us to reset per-cpu
259 		 * vcpu_info on resume.
260 		 */
261 		cpu_suspend_map = all_cpus;
262 		CPU_CLR(PCPU_GET(cpuid), &cpu_suspend_map);
263 		if (!CPU_EMPTY(&cpu_suspend_map))
264 			suspend_cpus(cpu_suspend_map);
265 	}
266 #endif
267 #endif
268 
269 	/*
270 	 * Prevent any races with evtchn_interrupt() handler.
271 	 */
272 	disable_intr();
273 	intr_suspend();
274 	xen_hvm_suspend();
275 
276 	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
277 
278 	if (!xen_suspend_cancelled) {
279 		xen_hvm_resume(false);
280 	}
281 	intr_resume(xen_suspend_cancelled != 0);
282 	enable_intr();
283 
284 	/*
285 	 * Reset grant table info.
286 	 */
287 	if (!xen_suspend_cancelled) {
288 		gnttab_resume(NULL);
289 	}
290 
291 #ifdef SMP
292 	if (!CPU_EMPTY(&cpu_suspend_map)) {
293 		/*
294 		 * Now that event channels have been initialized,
295 		 * resume CPUs.
296 		 */
297 		resume_cpus(cpu_suspend_map);
298 #if defined(__amd64__) || defined(__i386__)
299 		/* Send an IPI_BITMAP in case there are pending bitmap IPIs. */
300 		lapic_ipi_vectored(IPI_BITMAP_VECTOR, APIC_IPI_DEST_ALL);
301 #endif
302 	}
303 #endif
304 
305 	/*
306 	 * FreeBSD really needs to add DEVICE_SUSPEND_CANCEL or
307 	 * similar.
308 	 */
309 	DEVICE_RESUME(root_bus);
310 	bus_topo_unlock();
311 
312 	/*
313 	 * Warm up timecounter again and reset system clock.
314 	 */
315 	timecounter->tc_get_timecount(timecounter);
316 	inittodr(time_second);
317 
318 #ifdef EARLY_AP_STARTUP
319 	thread_lock(curthread);
320 	sched_unbind(curthread);
321 	thread_unlock(curthread);
322 #else
323 	if (smp_started) {
324 		thread_lock(curthread);
325 		sched_unbind(curthread);
326 		thread_unlock(curthread);
327 	}
328 #endif
329 
330 	resume_all_fs();
331 	resume_all_proc();
332 
333 	EVENTHANDLER_INVOKE(power_resume);
334 
335 	if (bootverbose)
336 		printf("System resumed after suspension\n");
337 
338 }
339 #endif /* __amd64__ || __i386__ */
340 
341 static void
342 xctrl_crash(void)
343 {
344 	panic("Xen directed crash");
345 }
346 
347 static void
348 xctrl_shutdown_final(void *arg, int howto)
349 {
350 	/*
351 	 * Inform the hypervisor that shutdown is complete, and specify the
352 	 * nature of the shutdown. RB_HALT is not handled by this function.
353 	 */
354 	if (KERNEL_PANICKED())
355 		HYPERVISOR_shutdown(SHUTDOWN_crash);
356 	else if ((howto & RB_POWEROFF) != 0)
357 		HYPERVISOR_shutdown(SHUTDOWN_poweroff);
358 	else if ((howto & RB_HALT) == 0)
359 		/* RB_POWERCYCLE or regular reset. */
360 		HYPERVISOR_shutdown(SHUTDOWN_reboot);
361 }
362 
363 /*------------------------------ Event Reception -----------------------------*/
364 static void
365 xctrl_on_watch_event(struct xs_watch *watch, const char **vec, unsigned int len)
366 {
367 	const struct xctrl_shutdown_reason *reason;
368 	const struct xctrl_shutdown_reason *last_reason;
369 	char *result;
370 	int   error;
371 	int   result_len;
372 
373 	error = xs_read(XST_NIL, "control", "shutdown",
374 			&result_len, (void **)&result);
375 	if (error != 0 || result_len == 0)
376 		return;
377 
378 	/* Acknowledge the request by writing back an empty string. */
379 	error = xs_write(XST_NIL, "control", "shutdown", "");
380 	if (error != 0)
381 		printf("unable to ack shutdown request, proceeding anyway\n");
382 
383 	reason = xctrl_shutdown_reasons;
384 	last_reason = reason + nitems(xctrl_shutdown_reasons);
385 	while (reason < last_reason) {
386 		if (!strcmp(result, reason->name)) {
387 			reason->handler();
388 			break;
389 		}
390 		reason++;
391 	}
392 
393 	free(result, M_XENSTORE);
394 }
395 
396 /*------------------ Private Device Attachment Functions  --------------------*/
397 /**
398  * \brief Identify instances of this device type in the system.
399  *
400  * \param driver  The driver performing this identify action.
401  * \param parent  The NewBus parent device for any devices this method adds.
402  */
403 static void
404 xctrl_identify(driver_t *driver, device_t parent)
405 {
406 	/*
407 	 * A single device instance for our driver is always present
408 	 * in a system operating under Xen.
409 	 */
410 	BUS_ADD_CHILD(parent, 0, driver->name, 0);
411 }
412 
413 /**
414  * \brief Probe for the existence of the Xen Control device
415  *
416  * \param dev  NewBus device_t for this Xen control instance.
417  *
418  * \return  Always returns 0 indicating success.
419  */
420 static int
421 xctrl_probe(device_t dev)
422 {
423 	device_set_desc(dev, "Xen Control Device");
424 
425 	return (BUS_PROBE_NOWILDCARD);
426 }
427 
428 /**
429  * \brief Attach the Xen control device.
430  *
431  * \param dev  NewBus device_t for this Xen control instance.
432  *
433  * \return  On success, 0. Otherwise an errno value indicating the
434  *          type of failure.
435  */
436 static int
437 xctrl_attach(device_t dev)
438 {
439 	struct xctrl_softc *xctrl;
440 
441 	xctrl = device_get_softc(dev);
442 
443 	/* Activate watch */
444 	xctrl->xctrl_watch.node = "control/shutdown";
445 	xctrl->xctrl_watch.callback = xctrl_on_watch_event;
446 	xctrl->xctrl_watch.callback_data = (uintptr_t)xctrl;
447 	/*
448 	 * We don't care about the path updated, just about the value changes
449 	 * on that single node, hence there's no need to queue more that one
450 	 * event.
451 	 */
452 	xctrl->xctrl_watch.max_pending = 1;
453 	xs_register_watch(&xctrl->xctrl_watch);
454 
455 	EVENTHANDLER_REGISTER(shutdown_final, xctrl_shutdown_final, NULL,
456 	    SHUTDOWN_PRI_LAST);
457 
458 	return (0);
459 }
460 
461 /**
462  * \brief Detach the Xen control device.
463  *
464  * \param dev  NewBus device_t for this Xen control device instance.
465  *
466  * \return  On success, 0. Otherwise an errno value indicating the
467  *          type of failure.
468  */
469 static int
470 xctrl_detach(device_t dev)
471 {
472 	struct xctrl_softc *xctrl;
473 
474 	xctrl = device_get_softc(dev);
475 
476 	/* Release watch */
477 	xs_unregister_watch(&xctrl->xctrl_watch);
478 
479 	return (0);
480 }
481 
482 /*-------------------- Private Device Attachment Data  -----------------------*/
483 static device_method_t xctrl_methods[] = {
484 	/* Device interface */
485 	DEVMETHOD(device_identify,	xctrl_identify),
486 	DEVMETHOD(device_probe,         xctrl_probe),
487 	DEVMETHOD(device_attach,        xctrl_attach),
488 	DEVMETHOD(device_detach,        xctrl_detach),
489 
490 	DEVMETHOD_END
491 };
492 
493 DEFINE_CLASS_0(xctrl, xctrl_driver, xctrl_methods, sizeof(struct xctrl_softc));
494 
495 DRIVER_MODULE(xctrl, xenstore, xctrl_driver, NULL, NULL);
496